1. Field of the Invention
The present invention relates to a sensor circuit, and more particularly, to a sensor circuit having a bridge sensor element.
2. Description of the Related Art
An output signal of a sensor element (sensor signal) is generally minute, and thus, is required to be amplified by a sensor circuit in order to be applied to an electronic circuit using a sensor element.
In recent years, miniaturization of electronic equipment is proceeding, and miniaturization of a sensor circuit built therein is also proceeding. Miniaturization of a sensor circuit results in a more minute sensor signal. In order to use a sensor signal which is a minute signal in ordinary electronic equipment, a higher amplification factor is necessary in an amplifier in the sensor circuit. On the other hand, a sensor circuit is required to operate at higher speed. A high amplification factor and high speed operation are generally mutually contradictory. In order to attain those requirements, hitherto, the current consumption of the amplifier is high (see, for example, Japanese Patent Application Laid-open No. 2010-181211).